Physical and chemical properties of tritium (T) as a radioisotope of hydrogen are introduced with comparison of those of protium (H) and deuterium (D). Because of large mass differences among the three isotopes, isotope effects in physical and chemical properties are most appreciable compared to those appeared in all other elements. In addition, T often presents specified properties in physics, chemistry and biology owing to its radioactivity and dilute use, which never appear in H and D.

Modulated symmetries have recently emerged in the context of fracton topological phases―unusual topologically ordered phases admitting fractionalized excitations with mobility constraints. Via gauging dipole symmetry, which is one of the modulated symmetries, we construct a new type of field theory hosting dipole of anyons. The result would contribute to better understanding of fracton topological phases.

After the discovery of the Higgs particle in 2012, the particle physics made it an inevitable target to search for a new physics beyond the standard model (SM). There are direct and indirect ways to detect an evidence of new physics in experiment. A representative case for the former is the proton decay. The latter tries to find the deviation between the experiment and the SM prediction, to which the lattice QCD simulation can contribute. The PACS Collaboration based on University of Tsukuba carry out a so-called master field simulation of 2+1 and 2+1+1 flavor lattice QCD to search for a new physics beyond SM. A typical example is the determination of |V_us|, which is an element of the CKM (Cabibbo–Kobayashi–Maskawa) matrix in SM, from the K meson semileptonic decay experiment. At present the lattice QCD results suggest 2σ deviation from the unitarity condition of the CKM matrix required in SM.

Double Majorana Kramers pairs (MKPs), protected by crystalline symmetry, can exhibit electric multipole response in time-reversal symmetric topological superconductors. Coupling between MKPs and dynamic strains has been proposed to generate anisotropic surface spin currents, revealing new phenomena tied to Majorana multipole properties.

This review introduces a study that explores how two surface reconstructions with similar formation free energies mix on the growing surface of GaN―one with Ga adatoms and the other with H adatoms. Their indirect interaction via surface charge is modeled using the Ising model. The partition function is evaluated to obtain thermodynamic properties.